This is the last version to support Zig older than 0.14.0-dev.1421+f87dd43c1, such as Zig 0.12.0, 0.12.1, 0.13.0, and 0.14.0-dev.91+a154d8da8.
The reason to stop supporting them is because of the breaking change in Zig standard library, in std.builtin.Type - its fields were renamed.
If you need to use zon_get_fields with the current dev build of Zig (0.14.0-dev.1421+f87dd43c1 or later), do not use this version. Get the latest version instead.